Model rendering overhaul

[weaverryan]

Q	A
Bug fix?	yes
New feature?	yes
Tickets	None
License	MIT

Hi!

tl;dr

BEFORE:
<input
    data-model="firstName"
    data-action="live#update"
>

AFTER:
<input
    data-model="firstName"
>

This PR makes it so that you only need to use data-model to bind an input to a LiveProp on your component object. This also introduces:

A) model modifiers (e.g. data-model="on(change)|norender|firstName" to update the model on change and skip re-rendering)

B) A new way to "opt in" to the name attribute being used in place of data-model: you now add a data-model to the form tag surrounding your fields: <form data-model"*">.

All of this is explained more in the CHANGELOG and documentation.

The motivation behind this change was actually to fix a bug. If you typed into field (A), then quickly typed into field (B) before the re-render Ajax request finished from changing field (A), when that Ajax call did finish, it would "replace" your custom changes to field (B). Basically, what you just typed disappears. Fixing this meant making live_controller.ts listen to the input event in all situations and track "unsynced inputs". And since we were now listening to the input event all the time, it seemed logical to no longer require the user to do this manually with data-action="live#update".

This PR also overhauls the test suite to make it much more readable and user friends 🌞 and also completes the conversion to TypeScript by removing all of the TS warnings.

Cheers!